I remember doing a sub-50 though, will put up a "Hello GTP" photo when I get home
You could do with less downforce though, I let my car get all the way to 438km/h, and still managed to keep it flat throughout the track apart from the first and last corners.
I also made some laps with the X2010 in Tokyo. It feels so fast due to all those trees and so on...
I don't remember what was my best lap, but is should be something above 50 seconds...